I always love seeing more done in the web component space. I think Lit has the no build process captured pretty well and they include things such as a router.

I do prefer the style of of your components more, where you separate out the script and styles with html tags. I don't know if one way or the other is superior for performance, I but just like the separation verse the templated strings in Lit.

With build tools being so straightforward now-a-days, I struggle to see the value in the build less approach. One use case I can think of is maybe a constrained environment where the application contains some kind of customizable user components fully in the browser like a reporting WYSIWIG of some kind.

Is there a particular reason you prefer this approach?